This invention relates to a fibre-optic laryngoscope spatula having a light-exiting first end and an opposite second end and being of the kind comprising a base part and with an exchangeable light-guide part having a spring-loaded coupling member.
Light guides, while being used, undergo a natural ageing process, during which the optical properties, in particular the transparency, of the light guides deteriorate. The light guides in the fibre-optic laryngoscope spatula are subject to this ageing process to a particularly pronounced degree, since they are exposed to violent thermal shocks during cleaning and sterilization, which are necessary after every use of the fibre-optic laryngoscope spatula, and the end faces of the light guides may suffer mechanical and chemical/thermal damage. As a rule, therefore, light guides in fibre-optic laryngoscope spatulas become unusable relatively quickly and when the other components of the fibre-optic laryngoscope spatula still have good practical properties.
So that the period of practicability of the fibre-optic laryngoscope spatula as a whole is not determined by the relatively short period of practicability of the light guides contained in it, fibre-optical laryngoscope spatulas with an exchangeable light-guide part have been developed. The advantage of such spatulas is that, after the transparency of the light-guide bundle falls below a particular threshold in relatively wide wavelength ranges due to ageing, it is only necessry to replace the old light-guide part with a new light-guide part. There is no need to purchase a complete new fibre-optic laryngoscope spatula.
A fibre-optical laryngoscope spatula with an exchangeable light-guide part is disclosed in U.S. Pat. No. 4,570,614. According to U.S. Pat. No. 4,570,614, a plastics part provided with the light guide is pressed into a base part of the fibre-optic laryngoscope spatula, the base part being suitably shaped to receive this plastics part. Once the plastics part with the light guide and the base part have been pressed together, they can only be separated from one another with difficulty and with some inconvenience since a base-part recess receiving the plastic part with the light guide has a completely continuous wall with an exact fit.
Another fibre-optic laryngoscope spatula with an exchangeable light-guide part is known from EP-A-0,586,972. In this known fibre-optic laryngoscope spatula, a light-guide bundle is arranged in a light carrier designed as a removable small angular metal tube. This makes it possible to exchange the light-guide bundle for a justifiable outlay when it becomes unusable. According to EP-A-0,586,972, the removable tube with the light-guide bundle is installed by first pushing one leg into a tube or recess provided in a first region of the fibre-optic laryngoscope spatula and is then retained in position by pivoting the other leg laterally into a recess or orifice provided in a second region of the fibre-optic laryngoscope spatula.
In addition to the light guide, there is another part of a fibre-optic laryngoscope spatula which is subject to increased wear. This other part is a spring-loaded coupling member, e.g a spring-loaded coupling pin, which, when the fibre-optic laryngoscope spatula is locked into a laryngoscope handle, engages in a corresponding inner recess in the coupling region of the laryngoscope handle. This spring-loaded coupling member, which is often designed as part of a spring-loaded catch, e.g. a ball catch, may lose its tension force as a result of frequent locking and unlocking operations and as a result of thermal shocks and chemical/thermal effects caused by frequent cleaning and autoclaving operations which are necessary after every use of the fibre-optic laryngoscope spatula. It is therefore desirable to have the possibility of exchanging not only the light-guide part, but also the part of the fibre-optic laryngoscope spatula which contains the spring-loaded coupling member. This is not possible, however, either in the known fibre-optic laryngoscope spatula disclosed in U.S. Pat. No. 4,570,614 or in the known fibre-optic laryngoscope spatula disclosed EP-A-0,586,972, where the spring-loaded coupling member is integrated into the base part of the fibre-optic laryngoscope spatula.
Another known fibre-optic laryngoscope spatula is the "Emac" type by the company Welch Allyn. This known type of fibre-optic laryngoscope has an exchangeable light-guide part which is designed in such a way that its spring-loaded coupling member or pin is seated in the exchangeable light-guide part and is always replaced simultaneously with the latter. This known Welch Allyn fibre-optic laryngoscope spatula can thus be broken down into two basic parts--the light-guide part with the spring-loaded coupling pin and the base part which has no movable components. Consequently, the base part is particularly robust and is rarely susceptible to faults. All those parts of the fibre-optic laryngoscope spatula which are subject to more rapid wear caused by ageing and which are susceptible to faults are located in the exchangeable light-guide part. Advantages therefore also arise in the area of sterilization which, if appropriate, can be carried out separately in differently controlled cycles for the two basic parts.
A disadvantage of the known Welch Allyn fibre-optic laryngoscope spatula is that the base part and the light-guide part are connected together by means of a screw, as disclosed in U.S. Pat. No. 4,958,624. The necessary opening and closing of the screw connection to exchange the light-guide part requires the use of a screwdriver which is inconvenient and laborious, especially since fibre-optic laryngoscope spatulas are used in the medical/surgical sector in which screwdrivers are not included in the tools of the trade which are constantly available. Moreover, the screw may be misplaced or lost completely due to carelessness when the light-guide part is being exchanged, with the result that time may have to be spent in looking for the screw or in procuring a replacement screw.
The object on which the invention is based is to provide a fibre-optic laryngoscope spatula with a base, part and with an exchangeable light-guide part having a spring-loaded coupling member, in which spatula the light-guide part can be exchanged in a simple way without any aids.